Patent document, DE 10 2009 047 624 A1 discusses magnetic field sensors for measuring magnetic fields. The magnetic field sensors have at least one magnet core, made of a soft magnetic material, which extends along a longitudinal axis. The magnet cores discussed in DE 10 2009 047 624 A1 are configured axially symmetrically with regard to their respective longitudinal axis. The magnet cores can furthermore have curved surfaces, in particular rounded terminal segments, and/or projecting or tapered center segments.